Sanyo VM 4509 DC adapter

[MissArgent]

So, I've got a Sanyo VM 4509 that needs to be powered via the DC adapter, which is a little unusual since all of the photos i've found online show a cable built in the monitor. the system doesn't mention the exact amperage it needs anywhere, but does identify it as needing 12 volts center negative. I can't find a service manual anywhere - anyone know what amperage it needs?

 

[Hugo Holden]

It says 17W power consumption on 12V, so the adapter would have to be capable of a minimum of 17/12 Amps. So a 1.5A rated adapter would just do it, but if you used a 2A capable one it (the adapter) might run a little cooler and a 3A rated one even better. There would be little point in using an adapter over 4A capable. The higher current range rated adapters might be a little more tolerant of the initial turn on surge load.

Well spotted on the center negative pin, most adapters have center positive pin.

 

[Chuck(G)]

"Well spotted on the center negative pin, most adapters have center positive pin. "

That's one of the things I hate about barrel connectors--no convention universally observed, including the same connector used for AC supplies.

Of course, putting AC on a connection meant for DC, or a reversed polarity on the connector wouldn't have any bad effects would it?

 

[snuci]

It also states 120V 33 watts. Are you sure the AC cord wasn't removed? Looks like the cord would fit in the hole to the left of the 12v barrel connector.

 

[MissArgent]

Yeah, normally there's a cord running in there with the ones i've found photos of online. I kinda hinted at that in OP but didn't really word it well. Unfortunately, a cursory examination inside the chassis didn't really reveal anything for it to connect to so far as I could tell so I assume that DC jack's my only option.

 

[GiGaBiTe]

Well spotted on the center negative pin, most adapters have center positive pin.

There was a shift in the early to mid 90s of barrel connectors going from center negative to center positive, where most devices before that time had center negative and most devices after had center positive.

I used to have a pile of old 70s, 80s and early 90s wall warts and the good majority of them were center negative. I ended up scrapping or throwing out all of them because they had drifted so far off their original voltage spec that they were unsafe to use. The only two I kept were for my Sega Genesis and CD, but even those got restuffed with newer switching supplies because the old transformers had drifted far out of spec. Originally 9 or 10v, they now put out 14-17v, which is far too high for an LM7805.